The present disclosure relates to an anode active material including graphite, and a battery using the anode active material.
In recent years, portable electronic devices such as camcorders, cellular phones and portable computers have emerged, and the portable electronic devices have been reduced in size and weight. Accordingly, batteries, specifically secondary batteries have been actively developed as portable power sources for the electronic devices. Among them, a lithium-ion secondary battery has been a focus of attention as a battery capable of achieving a high energy density.
However, in the lithium-ion secondary battery, the voltage is high, and the oxidation potential of a cathode is very noble, and the reduction potential of an anode is very base, so a nonaqueous solvent used for an electrolyte solution is decomposed as a side reaction except for battery reactions to generate a gas. Therefore, it has been considered that as a gas absorbing material, a carbon material having a high specific surface area is included in any batteries including primary batteries and secondary batteries (for example, refer to Japanese Patent No. 3067080 and Japanese Unexamined Patent Application Publication No. H8-24637). Moreover, it has been considered that a mixture of a plurality of carbon materials is used, although the mixture is not used as a gas absorbing material (for example, refer to Japanese Patent No. 3216661, and Japanese Unexamined Patent Application Publication Nos. H6-111818, 2001-196095, 2002-8655 and 2004-87437).